The reason clubs are folding is because its becoming increasingly difficult to replace players when they move away, retire or otherwise reduce their availability. In the past clubs might have been able to rely on a steady trickle of new, younger players coming in, but since cricket disappeared from FTA tv that trickle has dried up entirely.
There are lots of zero-sum-game activities some clubs get up to to steal players off other clubs, which might give them a temporary boost, but this comes at the cost of another club going under, so in the grand scheme of things this isn't really a helpful attitude. I see clubs boasting about how they're growing and getting promoted, but look behind the façade and they've basically just asset stripped several other clubs from their area. There is nothing admirable in this approach.
Ultimately, the only way for a club to stay alive in a sustainable manner is to put the huge amount of work into setting up and running a junior section. But again, without international cricket on FTA tv, kids fail to fully engage, drift off into other activities, and this ends up being incredibly hard work for very little positive outcome.